package learn.emp02.ex21;

public class Main {
    public static void main(String[] args) {
        double PI = 4*(1.0-1.0/3.0+1.0/5.0-1.0/7.0+1.0/9.0-1.0/11.0+1.0/13.0);
        System.out.println(PI);
    }
}
